Research On Knowledge-base Thematic Data Generalization In GIS

Geographic Information System (GIS) has been one of important tools, which is used in research and management on geographic, thematic Data is important component of geographic data in GIS. The generalization of thematic data is one of data operations in GIS, which provides multi-scale or multi-resolution data for some applications.As the generalization of topographic data, thematic data generalization needs the support of generalization knowledge to satisfy the use requirements and reflect the main geographic nature. The generalization knowledge of thematic data generalization not only includes map knowledge that is used to represent thematic data as thematic map, but also includes the nature and distribution rules of geographic phenomena by the thematic data. The representation and application of the generalization knowledge are also key problems of the research on thematic data generalization.Based on the current researches, the thesis tries to analysis the main types and the main causes of thematic data generalization, and focus the attention on generalization-rules and how to combine with generalization operations. Base on the generalization function and the spatial analysis function of GIS software, the thesis implements thematic database generalization on classification of agricultural lands.